Method of isolating alcohols or phenols from mixtures



Patented Oct. 29, 1929 PATENT. OFFICE FRANZ OTTO ZEITSCHLEL, OI HAMBURG,GERMANY METHOD ISOLATING ALCOHOLS OR PHENOLS FRO]! MIXTURES Io Drawing.Application filed July 13, 1925, Serial No. 48,875, and in GermanyAugust 1, 1924. 7

Pure alcohols or phenols can be converted into boric acid esters byallowing them to react with the mixed anhydride of boric acid and aceticacid B(OCOCH The triborates produced can then be readily obtained pureafter distillation or crystallization. H

It has now been found that this reaction of hydroxylated compounds ofthe alcohol 10 and phenol groups, which takes place smoothly, can notonly be used in connection with pure alcohols but that with theassistance of this reaction it is possible almost quantitatively toisolate alcohols of all kinds; primary, secondary, or tertiary and alsophenols'from mixtures containing such alcohols or phenols, eitherseparately or in admixture, without injuring the by-products which arepresent. The method of operation is the same in all cases, regardless ofwhether the mixture contains only alcohols, only phenols, or compoundsbelonging to both groups. After having ascertained, as by acetylizingthe quantity. of alcohols present in a mixture to be examined, thecalculated quantity of the double anhydride is prepared and added to theabove mixture. Decomposition takes place with the development of a smallamount of heat, and it is only necessary at ordinary or preferably atreduced pressure to distill ofi the acetic acid (or its homologues)formed, and the more readily volatile by-products from the tri-borateswhich are more difiicult to volatilize. If the borates (or analogues)are solid they can be further purified before splitting up byrecrystallization from a suitable solvent. The esters obtained aredecomposed by the addition of water or aqueous alkalies and thealcoholic dissociation products are rectified or recrystallized withsteam for purification.

The new method is more particularly applicable to the field ofturpentine chemistry and the ether oils but it may also be used forother purposes.

a manner very analogous to the boric acid-acetic acid-anhydride methodthe reaction can also be carried out with the corresponding doubleanhydride's of arsenic acid As(OCOCH of antimonic acid Sb(OCOCH,,) orphos boric acid P(OCOCH The use of an ydrides of other organic acids mayafford advantages in comparison with the acetic acid anhydrldes.

Examples I. Sapom'fied Japanese pep ermi/nt oil.- 702 gr. with a 54.2%content 0 alcohols were treated with a solution of 45 gr. B(OH), in 225gr. acetic acid anhydride. During the o0 vacuum distillation 353indifferent oil passed over in addition to the acetic "acid, while whencooling 347 gr. solidifiable borates remained as retort residue. Afterneutralization 332 gr. of alcoholic constituents were obtained therefromby steam distillation, which alcoholic distillate solidified in thecooler, and from the constants: 03 20.903, 02 2 35.60 was found to bealmost pure menthol.

A second treatment of the indifferent oil only gave 14.3 gr. alcoholicconstituents.

, II. Citromll oil 0e3 Zon.38O gr. with a 57.6% content of alcohols weretreated with a solution of 15 gr. B(OH) in gr. acetic acid anhydride.After vacuum distilla- 76 tion, 120 gr. of borate were obtained as aresidue which, after neutralization, produced by steam distillation 107gr. of alcoholic constituents 0.904 -2.50, which reacted with pulverizedCaCl and Was found to be mainly 80 geraniol.

III. Shz'u 0z'Z.-285 gr. (with d :0.878 and 5 :11.00) of which the mainportion consists of linalool, was treated with 50 gr. B 011) and 250 gr.acetic acid anhydride. A er vaccum distillation, there remained 278 gr.borate, which were neutralized with a soda solution and distilled withsteam and produced 270 gr. of almost pure linalool (03 :0.870, 11:15.00). The indifl'erent oil amounting to 78 gr. showed however (Z:0.960, m +8.50".

IV. For examining the accuracy of the method benzyl acetate wassubjected to the reaction with 94% ester or 6% benzyl alcohol. 200 gr.of this mixture were treated with 3 gr. B(OH) +15 gr. acetic acidanhydride. After vacuum distillation there remained a residue of 10 gr.which was split up with a soda solution and produced 10 gr.

benzyl alcohol. The ester content of the non-reacting parts hadincreased to 100%. The course of the method was therefore quantitative.

It was further found that the formation of diflicultly volatilizableesters can also be obtained if the boric acid or its anhydrides or itanalogues (arsenic acid, antimonic acid, hos horic acid or theiranhydrides), are a owe as such to act on the mixture in the presence ofheat. The reaction takes place according to the following formulae:

where R indicates any suitable alcohol or henol residue, and where B canbe replaced by A5, Sb or P. i g It is onl necessary to take care thatthe water pro need during the reaction is removed by distillation orotherwise. The

quantity of the distilled water gives a direct 80 to100 C. The water isvery soon separated andis condensed in the cooler in the form of drops.When producing a slight vacuum it distils ofi with a small quantity ofoil and can be measured in the receiver (32 gr.). After about two hoursthe separation of the water ceases and the boric acid has passed intosolution. With a good vacuum the indifferent oil is now completelydistilled off and the borates remaining as a residue are decomposed bymeans of a soda solution and the alcohols are driven oil by steam. Thereare obtained:

Alcohols:

295 gr. with J 0.941, 01. 9.00 Indifferent oil:

310 gr. 605 gr.

It was further found that when carrying out the treatment in stagesaccording to the borate method a substantial separation of alcohols ofdifferent classes could be effected. This possibility is based upon thefact that the reaction capacit of the primary alcohols is greater andquic er than that of the secondary alcohols, that of the secondary isgreater than that of the tertiary alcohols,

withd t 1.002, (1, 2+ 10.50

so that b suitably controlling or measuring the addition of the boricacid or its analo es, as may be desired, it is possible to obtain cm amixture either the primary or primary. and secondary or if the primaryare not present, the secon ary.

VI. From a mixture of 60 gr. geraniol and 140 gr. terpineol, which atthe start will not in any mayrea'ct with calcium chloride, 72 gr. ofalcohols are obtained by treatment with .10 gr. boric acid in the'manner described,

distillation of the indifferent part and decomposition of the remainingborates, which smoothly react with calcium chloride and these prove'tobe high percentage geraniol. In the distillate the terpineol has beencorrespondingly enriched.

VII. From a mixture of 60 140 gr. terpineol it is poss borneol and le inquite a similar manner by means of 10 gr. boric acid to isolate about 75gr. difiicultly volatilizable borates, which become solid in the coolerupon steam distillation and are mainly found to be borneol.

VIII. From a mixture of 30 gr. geraniol, 30 gr. borneol and 140 gr.terpineol it is possible in a quite similar manner to separate by meansof the borate method 120 gr. of almost pure terpineol from gr.diflicultly volatilizable geranyl-bornyl-borates.

It will be understood that, instead of the artificial mixtures herereferred to, oils occurring'in nature or technical oils can be used. I I

It will be understoodthat where in the claims I employ the terminorganic poly-, basic acids of the third and fifth periodic groups Imean to include by such term the acids of boron, phosphorus, arsenic andantimony, and their anhydrides; and where generally I employ the termacid or acids I include thereby also the anhydride or anhydrides.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is 1. The method of isolating alcohols and Iphenols from mixtures containing the same, which consits in producingdifiicultly volatilizable boric acid esters from. said alcohols andphenols by esterifying said mixture with boric acid only to the extentof forming the esters of said alcohols and phenols, distilling off thevolatile admixtures, and decomposing the remaining esters by adding asolution of alkalies in water and further purifying the regeneratedalcohols and phenols.

2. The method of isolating alcohols and and phenols from mixturescontaining the same, which consists in producing difl'icultlyvolatilizable boric acid esters from' said alcohols and phenols byesterifying said mixture with boric acid only to the extent of formingthe esters of said alcohols and phenols, disstilling off the volatileadmixtures, purifying the remaining esters in so far as they are solidby recrystallization, and then decomposing them bysadding a solution ofalkalies in water. I J

3. The method of isolating certain of the hydroxylated compounds of thealcohol and phenol groups from mixtures containing a plurality ofsuchcompounds, which comprises adding stoicheiometric quantities of boricacid corresponding to the molecular weight and the quantity of one ormore of the most reactive of such compounds, whereby difilcultyvolatilizablc boric acid esters of such compounds are produced,distilling off the volatile admixtures, and then hydrolyzing saidesters.

4. The method as set forth in claim 3, wherein the solid esters arepurified by recrystallization before hydrolysis.

5. The method as set forth in claim 3, wherein the filtrate is similarlytreated with boric acid to remove the more reactive hydroxylatedcompounds contained therein.

6(The method of isolating certain of the hydroxylated compounds of thealcohol and phenol groups from mixtures containing a plurality of suchcompounds, which comprises adding stoicheiometric quantities ofinorganic polybasic acids of elements of the third and fifth periodicgroups corresponding to the molecular weight and the quantity of one ormore of the most reactive of said hydroxylated compounds, wherebydifliculty volatilizable esters of such acids are produced, distillingoff the volatile admixtures, and then hydrolyzing said esters.

7. The method as set forth in claim 6, wherein the solid esters arepurified by recrystallization before hydrolysis.

SfThe method for isolating alcohols and phenols from mixtures containingthe same, which consists in treating said mixtures with quantities ofborating agents corresponding .to the quantities of alcohols and phenolscontained in the mixtures to produce difiicultly further purifying theregenerated alcohols and phenols.

10. The method of isolating alcohols and are so id by recrystallization,and then decomposing them by adding a solution of alkalies in water.

11. The method of isolating alcohols and phenols from mixturescontaining the same, which comprises reacting upon said mixtures with aninorganic-polybasic acid of an element of the third and fifth periodicgroups only to the extent of forming the esters of said alcohols andphenols, removing the water' from the reaction zone as ra idly as it isformed, distilling off the volati e, constituents, hydrolyzing theresidue, and separating the alcohols and phenols therefrom.

12. The method of isolating alcohols and phenols from mixturescontalning the same, which comprises'reacting u on sald mixtures with aninorganic polybasic acid of an element of the third and fifth periodicgroups and an or anic acid anhydride only to the extent of orming theinorganic acid esters of said alcohols and phenols, distilling off thevolatile constituents, hydrolyzing the residue, and separating thealcohols and phenols therefrom.

In testimony whereof I have afiixed my signature. DR. PHIL. FRANZ OTTOZEITSOHEL.

volatilizable boric acid esters from said alcohols and phenols andesterfying said mixture with said borating agents only to the extent offormin the esters of said alcohols and phenols, distilling oil thevolatile admixtures and decomposing the remainin esters by adding asolution of aqueous alka 'es and furtherpurifying the regeneratedalcohols and phenols.

9. The imethod of isolating alcohols and phenols from mixturescontaining the same, which consists in producing difiicultlyvolatilizable esters of inorganic polybasic acids of elements of thethird and fifth periodic groups from said alcohols and phenols byesterifying said mixtures only to the extent of forming the esters ofsaid alcohols and phenols, distilling off the volatile admixtures, anddecomposing the remaining esters by adding a solution of aqueousalkalies and

